1. Our Star, the Sun
One hot experience

2. Our Sun
The sun is more than 4.6 billion years old and will continue to burn for several billion more years.
The sun, a star, is a collection of gas – mostly hydrogen and helium.

3. Sunlight Sunlight arrives in 3 forms: Infrared (heat) Visible light
Ultraviolet light

4. Ultraviolet Light 3 classifications of UV light UVA = blacklight
UVB = tanning, sunburn, cancer
UVC = filtered out by the Earth’s atmosphere and never reaches us

5. Phosphors
Phosphors are substances that give off light, or fluoresce, when exposed to light.
Electrons energize the atoms in the substance to make them give off light

6. How do they Work? Tanning beds and Sun burns
– overexposure to UVB rays mutates DNA and may start cancer

7. How do they Work? Sunscreens/Sunblock Sunscreens absorb UVB light
Sunblocks block out UVB light

8. How do they Work? Bug Zapper –
Bugs are attracted to the UVA light because they think it is food or because of mating.
Mosquitos are not attracted. Why not?

9. How do they Work? Black Light
Phosphor coating absorbs UVB, UVC and visible light.
Only UVA is emitted

10. Uses for UV light Highlighters/stamp for readmission to theme parks
Killing germs/sterilization

11. Uses for UV light
Detect urine
Detect insects
CSI

12. Uses for UV light Detect counterfeit money
Forgery (paintings, antiques)

13. Uses for UV light
Tonic Water
Detergents
Detecting Minerals